It is known in the art to add a scavenger to a photographic element in order for the scavenger to prevent oxidized developing agent from reacting within the element at an undesired location or at an undesired point in time. In particular, it is undesirable for oxidized developer to diffuse away from the imaging layer in which it formed and into other color records where it can form dye in the wrong layer. In some formats, it can also be undesirable for toe scale and fog considerations to have oxidized developer form dye at early stages of development. Typically, scavengers reduce or eliminate oxidized developers without forming any permanent dyes and do not cause stains nor release fragments that have photographic activity. They are also typically rendered substantially immobile in the element by incorporation of an anti-diffusion group (a ballast) or by attachment to a polymer backbone.
Known scavengers for oxidized developers include ballasted hydroquinone (1,4-dihydroxybenzene) compounds as described in U.S. Pat. Nos. 3,700,453 and 4,732,845; ballasted gallic acid (1,2,3-trihydroxybenzene) compounds as described in U.S. Pat. No. 4,474,874; ballasted sulfonamidophenols as described in U.S. Pat. Nos. 4,205,987 and 4,447,523; and ballasted resorcinol (1,3-dihydroxybenzene) compounds as described in U.S. Pat. Nos. 3,770,431. Such known materials are insufficient in their activity, requiring high material usage, thus increasing cost, storage and handling concerns as well as requiring thicker layers, thus degrading sharpness through increased scatter path length. In addition, because these known materials are sensitive to oxidative conditions, they are often insufficiently stable upon long term storage. Finally, many of these materials form stains or colored residues during processing.
It is also known to use certain hydrazide compounds in color photographic elements as scavengers for oxidized developing agent. Thus, for example, U.S. Pat. No. 4,923,787 discloses the use of hydrazides of the formula ##STR2## wherein R.sup.1 is an electron-donating group, R.sup.2 is hydrogen, alkyl, alkoxy, aryl, aryloxy, aralkyl or amino and n is 1 or 2; and Japanese Patent Publication No. 4,238,347, published Aug. 26, 1992, discloses the use of hydrazides of the formula ##STR3## wherein R.sub.1, R.sub.2 and R.sub.3 are hydrogen, halogen, alkyl, alkenyl, alkoxy, aryloxy, alkylthio, arylthio, acylamino, sulfonyl, carbamoyl, sulfamoyl or sulfo,
R.sub.1 and R.sub.2 can connect to form a ring structure;
R.sub.4, R.sub.6 and R.sub.7 are hydrogen or alkyl;
R.sub.5 is alkyl, cycloalkyl, aralkyl, alkenyl, aryl or a hetero ring;
J.sub.1 is --CO--, --SO-- or --SO.sub.2 --;
J.sub.2 is --CO--, --SO--, --SO.sub.2 -- or --COCO--; and
n is zero or one.
U.S. Pat. No. 5,230,992, issued Jul. 27, 1993, also discloses color photographic elements containing a hydrazide compound to reduce color staining and color fog. The compounds disclosed have the formula ##STR4## wherein R.sup.11, R.sup.12 and R.sup.13 represent hydrogen, an aliphatic group or an aromatic group, R.sup.14 represents hydrogen, an alkyl group, an aralkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an amino group,.an alkoxycarbonyl group, an aryloxycarbonyl group or a carbamoyl group, G.sup.11 represents a carbonyl group, a sulfonyl group, a sulfinyl group, a ##STR5## group, or an iminomethylene group, and n is 0 or 1.
The hydrazide compounds described above suffer from many of the same disadvantages and deficiencies as the hydroquinone, gallic acid, sulfonamidophenol and resorcinol compounds. In particular, these hydrazide compounds are especially deficient in regard to activity and long-term storage stability.
It is an objective of this invention to provide a new class of reactive scavengers for oxidized developer which can be incorporated in a wide range of photographic elements, and especially in color elements to prevent color contamination between layers, to prevent stain and to reduce fog. It is a particular objective of this invention to provide a new class of reactive scavengers that have high activity, that have excellent stability upon long-term storage and that do not leave colored residues after processing.